Method of tempering.



w. E. Mcmmson.

METHOD OF TEMPERING.

APPLIQATIOK TILED $215.9, 1908.7

. Patented 0t.4"19 1o. I

' warm.

" f To all whomitmayconcem: 7

Be it known that 1, XVILLIAM E. brom ne. son, a citizen of. the United States,- and rcsr WILLIAM E. moxsnson,

It 1 UNITED TATESPATENT OFFICE.

OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOR TO GILLETTE SAFETY-RAZOR COMPANY, OF BOSTON MASSACHUSETTS, CORPOBATIQN OF MAINE.

' mmson or rmrrnnmd Specification of Letters Patent. 7 Patented Oct, 4, 1910'.

Original implication illed'SeritemherQt-I, 1903, Serial No. 174,739. D ivieed and this application'fiiet'ldent'vof Camhridge,in the county ofllliddlesex and State of Massachusetts. have mvented anew and useful Method of Tempcring, of 'JlllCll the following is a specification.

This invention relates to the art of teni-j pering'steel, and is purticulnrlf, applicable 10 to the texupcrirm of thin sheet stec articles such as the blades employed in the safety razor shown and described in S. Letters Patent, No. 775,134, granted on-thc th day of November, 1904, on theapplication 15 of King C. Gillette, this applicationbeing a division of lll V-1)1'lOl" application, Soria No. 174,739, filed Septemherflfi;1903, in which a method of hardening said blades and similar articles is described nnd'clsimed. '111 hardening thcserbhides it will'oecasion-V ally happen that lhey'will be sliqhtly rimhound or dished when cold, and drawing a the temper of such blades in the ordinary way will have no effect on this dishing. 1-

have discovered, however, that blades thus deformed can be restored to, their origin-J1 flatness by confining them compactly butween flat plates or abutments and drawing their 'lexnper in a hot bath while so conlined; and l have also found that the flainess of blades which have not been deformed f b the hardenin" vroccs-i can be )rcscrvcd Y a o l r by tempering them 111 the sumo way. In

practice, I temper anuniber of hladcssnnuh taneouslv by stacking them one upon another. .lVhen the temper of such blades or-- other articles is drawn in' this lnanno the P heat has to pass intoand out of the'lilades mainly throughtheexposed edges of the -latter, and the results secured appear to be due to this factand to the further fact that the blades are compactly confined under pressure and between cud plates orabutments, so that. when the molecular strains are removed or diminished by the heating operation the tendency is for the blades to become or remain flat, and when they are again cooled they must do so \\'llll0llt.(ll$- tortion. In the accompanying drawings, I have illustrated an apparatus useful in practicing rem-nar s, 1906. Serial No. 300,231.

pered; Fig. 2 is a top plan view of the same; and Fig. 3 is a. plan view of one of the blades above. referred to. V 7

Referring to the drawings, 2 represents a frame, preferably made-of iron or steel, which is shown as consisting of 'a rectangular riminclosing two open spaces separated by a transverse partition 3. V

4 represents a thin shcet'rnetal blade such as 1s shown and described 111 the Letters Patent above referred to, 5+5 represent removable end plates which are preferably a little longer and wider than said blades and are enough thicker than the latter to be rigid to pressure, and 6-43 represent clamping screws passing through the end portions of the f ante 2, in position to bear upon the. corresponding end plates. e In practic ng my method with this apparatus, the open spaces in the frameLQ are each tilled with a stack of hardened blades -l. ousiniilar articles, each slack being sur: znonntcdat the corrc'spom-ling end of the l'rann by one of the plates 5 and hearing at its other end on the flat inner fllL'Q of the partition which should be at least as long and as wide as the blade Each stack is thereupon compacted by pressure applied to the currcspomling plate 5 through its clamp in screws 6, and'the frame with the contained star-ks of blades is then suspend d in a tempering bath or otherwiseexposed to heat and thereby subjected to the roper temperature for a suitable len th or timc, according to the tempcroequircd. After the operation has been completed the clamping, screws are unscrewed and the blades are rcmoved and separated. V a

Any other suitable apparatus may be 0mployed instead of the one above described.

My method of tempering above dcsuihed is useful not only on account of its ollieiency in preserving or restoring the flatness of the articles tempered, but also because it provides, if desired, for tempering a large number of such articles simultaneously and therefore quick and economically, as will be evident. It will also be evident that a thin steel article need not necewirily be flat or intended to be fiat inorder to be capable of being tempered according to my method, it being requisite merely that the end plates or abutnients shall conform to the desired shape of the artiel l V 2 i is 71,628

r I claim as my invention:

1. The herein described method of telnpering thin articles-of hardened steel, which consists in placing said hardened articles one directly upon another to form ,a stick, confining themnnder pressure nnd drawing the tem er thereof byimmersing said; stack in :1

1a hot bath. e

hot 11th. 1 s V 2. The herein, describedmcthod of tempering thinsteel articles, which consists in heating said articles and. hardening the same,

placing said hardened articles one directly uponanother to form n stack and confining confining the stack under pressure between rigid protecting surfaces which conform in contour to the articles when tempered, and subjecting said stack to-hent. o

4. The herein describedmethodofi tempering thin articles of hardened steel, which consists in placing said hardened articles one directly upon another to form a stack, confining the stack under pressure between rigid protecting surfaces which coufornr in contour to the articles when tempered, and'immet-sing said stack in a hot bath. i

In testimony whereof, 1 have hereunto subscribed my name this seventh day of February, 1906.

Witnesses: I E. D. CIIADWICK, Josnrn T. BRENNAN.

WILLIAM E. XICKERSOX. I .7 

